California investors made a formal offer to purchase the Sacramento Kings basketball team, the NBA said on Wednesday, in the hopes of staving off a competing bid that would move the team to Seattle.

The offer comes shortly after Seattle investors raised their bid to buy the team by $25 million to $550 million last week. The Seattle group hopes to rebrand the team as the SuperSonics to replace a beloved franchise lost to Oklahoma City in 2008.

The prospect of losing the Kings and leaving the California capital without a professional basketball franchise spurred Sacramento's mayor, himself a former NBA player, into action.